Vacuum switch



Aug. 16, 1966 H. c. Ross 3,267,247

VACUUM swITcH Filed July 15, 1963 V? b INVENTOR. 5 7 HUGH C. R055 I6 a@ Mmmm 43a 43 IE Aor the life of the switches. l point, the contacts of the units 11 and 12 may be con- United States Patent() Fice 3,267,247 VACUUM SWITCH Hugh C. Ross, 11915 Shadybrook, Saratoga, Calif. Filed July 15, 1963, Ser. No. 295,015 Claims. (Cl. 200-168) The present invention relates in general to electric switches, and more particularly to a vacuum switch.

An object of the present invention is to provide an improved vacuum switch. Anotheryobject of the present invention is to provide a vacuum switch that is adaptable for a greater variety of applications.

Another object of the present invention is to provide a vacuum switch that has greater durability and is less 'subject to d amage caused by shock.

Another object of the present invention is to provide a vacuumy switch that has improved lateral exibility yto reduce shock damage.

Another :object of the present invention is to provide an improved switch actuating arrangement for a vacuum switch.

Another object of the present invention is to provide a vacuum switch wherein jarring from the operation of the switch actuating arrangement is reduced.

v Another object of the present invention is to provide a vacuum switch wherein the timing for trip and reset is adjustable to accommodate various switching applications.

Another object of the present invention is to provide a vacuum switch wherein the speed of contact making and breaking is adjusta-ble.

Other and further objects and advantages of the present invention will be apparent to one skilled in the art from the following description taken in conjunction with the accompaying drawings, in which:

' FIG. 1 is a section View, partly in elevation, taken .along the longitudinal center line of the vacuum switch of the present invention.

FIG. 2 is a vertical section View taken along line 2 2 .of FIG. 1.

. FIG. 3 is a view of the vacuum switch taken alon-g Illustrated in FIGS. l-3 is the vacuum switch 10 of thenpresent invention, which comprises a single unit or .a plurality of conventional and well-known vacuum power switches, breakers or interrupters, such as units 11 and 12, which are connected mechanically in tandem for increasing the current or voltage capabilities thereof i From an electrical viewnected in series or series-parallel. While the units 11 and 12 may be referred to as Vacuum power units, it is well-known that the electrical contacts thereof may be immersed in an inert gas or a suitable liquid.

At the lowermost extremity of the vacuum switch 10 is located a ilat end or terminal metallic plate 15 having a cylindroid configuration. Fixed to the end plate 15 by screws 16 is a metallic tubular end coupling 17. On the inner wall 17a of the tubular coupling 17 are formed annular grooves 17b. Further, the tubular coupling 17 is formed with a reduced diameter wall which provides a shoulder 17c.

Seated on the shoulder 17e and having the lowermost portion thereof disposed within the tubular coupling 17 is an acrylic housing 20. rDhe housing 20, which is preferably a transparent cylinder, may also be made of epoxy glass, Pyrex or porcelain. As shown in FIG. l, the

housing 20 extends upwardly a suicient distance to substantially surround the Vacuum power switches 11 and 12.

Formed on the outer Wall of the housing 20 at the lowermost portion thereof are annular grooves 20a, which complement the annular grooves 17b of the metallic coupling 17 aligned therewith to form rings or annulars. An epoxy resin or other sealing compound is applied to the grooves 17b and 20a immediately prior to seating the housing 20 within the coupling 17. After the housing 20 is seated within the coupling 17, a hermetically sealed and mechanically locking joint is formed between the coupling 17 and the housing -20. Thus, a fastening and securing arrangement is provided, which produces an extremely strong joint and seal between the lowermost portion of the housing 20 and the coupling 17.

At the uppermost portion of the housing 20 are formed annular grooves 20h. Seated on the uppermost portion of the housing 20 is a metallic tubular coupling 21. Annular -grooves 21a are formed on the inner wall of the tubular coupling 21, which complement the annular grooves 2Gb of the housing 20 aligned therewith to form rings or annulars. An epoxy resin or other sealing compound is applied to the grooves 20b and 21a immediately prior to seating the coupling 21 on the housing 20. After the coupling 21 is seated on the housing 20, a hermetically sealed and mechanically locking joint is formed between the coupling 21 andthe housing 20.

Fixedly secured to the coupling 21 is a flat metallic terminal plate 22 in the form of a cylindroid. Attached in fixed relation to the plate 22 is a tubular'metallic coupling 23 and tixed to the tubular coupling 23 by screws 24 is a at metallic plate 25. The plate 25 and the coupling 23 may lbe considered a closure cap for the vacuum switch 10.

The vacuum power switches 11 and 12 are shock mounted for reducing any tendency to be damaged -by lateral thrusts or the like. At the lowermost portions of thevacuum power switches 11 and 12 are iixedly secured by screws 30 and 31, respectively, .rigid posts or feet 32 and 33, respectively. The supports orfposts 32 and 33 may be metallic or insulating material and have a cylindrical configuration.

Formed in the bottom of the posts 32 and 33 are openings 34 and 35, respectively, which receive screws 36 and 37, respectively. The screw 37 is received by an opening in the plate 15 to securely attach the post 33 to the plate 15. The screw 36 is received by an -opening 38 formed in a stationary metallic terminal. plate V39. In turn, the plate 39 is fixed by screws, not shown, to a stationary tubular metallic coupling 40. The coupling 40 is fixedly attached to the housing 20 by screws, not shown. Hence, the post 32 is held stationary by means of the plate 39, coupling 40 and housing 20. The metallic coupling or corona shield 40 is a cylindrical internall housing for center supports between successive power switches, such as 11 and 12, to eliminate the corona problem =at junctions between successive power switches.

Interposed between the rigid post 32 and the plate 39 is a yieldaible and yresilient washer or ring 42, which is made of suitable material, such as neoprene. Likewise, interposed .between the rigid post 33 and the plate 15 is a yielda-ble and resilient washer or ring 43, which is madeof suitable material, such as neoprene. In addition, a resilient washer 43a made of suitaib-le material, such as neoprene, is disposed between the plate 15 and the neck of the screw 37. A similar washer 42a is provided for the screw 36.

From this arrangement, the vacuum power switches 1 1 and 12 are shook mounted on the yieldiable and resilient rings or washers 4t2, 42a, 43 and 43a, whereby selfrealignment is attained and whereby sidewise thrusts or lateral impacts as well as longitudinal forces are absorbed. As a consequence thereof, there is reduced wear, tear and strain on supporting bearings, seals, couplings and the like. Further, damage resulting Ifrom shock during handling, shipping or use is also reduced.

Included in each vacuum power switch, such as switches 11 and 12, is a movable contact, not shown, and a stationary contac-t, not shown. The movable contact is mounted in its associated switch for axial movement between .a position engaging the stationary contact to form a closed circuit and a position removed from the stationary contact to provide an opened circuit.

Metallic, threaded operating rods 50` and 51 are attached in a conventional manner to the movable contacts, not shown, of the switches 11 and 1'2, respectively, for imparting axial movement thereto. As shown in FIG. 1, the operating rods 50 and 51 project o-ut of the vacuum power switches 11 and 12, respectively, throug-h stationary collars 52 and 53, respectively. Surrounding the rods 50 and 51, respectively, and secured to the collars 52 and 53, respectively, are terminal plates 54 and 55. A conductor 56 interconnects the terminal plate 55- and the switch 12. In a similar manner, a conductor 56' interconnects the flat plate -15 and the lower end of the switch 112. Likewise, a conductor 56 interconnects the plate 22 and the terminal plate 54. 'Ihe use of taps, such as screws '4\1a-441d, extending within the single full length acrylic housing to the vacuum power switches at the junction between successive vacuum power switches iacilitates the attachment of voltage grading capacitors, resistors and fiashover gaps.

Formed in the housing at the junction between successive vacuum power switches, such as 11 and 12, is an opening 20cd rRemovably attached to the housing 20 to cover the opening 20c is a window 20d. The window or panel 20d is sealed to the housing 20 by an adhesive or suitable gasket, or may be secured to the housing 20 by screws, such as sc-rews 41a and 41b. However, when removed, it airords an access to the junction between successive vacuum power switches for testing and adjusting connections and components thereabout after assembly is completed and while in the field.

Adjustably mounted on the threaded rods 50` and 5-1, respectively, in threaded engagement therewith are adjustably positioned heads 57 and 58. 'The head 57 has an upper reduced section, which forms an annu-lar shoulder 57a and a lower arcuate wall 57h. Seated on the shoulder 57a is .a return compression spring 60 which continuously ur-ges the operating rod 50 downwardly toward its contact closing position. The spring 60` is in continuous engagement with a bracket 61 that is bolted to a block 62. The block 62, in turn, is secured by screws to the tubular coupling 23.

In a like manner, the head 58 has a reduced upper section, which forms an annular shoulder 58a, and a lower arcuate wall 58b. Seated on the shoulder 58a is a return compression spring 63, which continuously urges the operating rod 51 downwardly toward its contact closing position. The spring 63 is in continuous engagement with the plate 3-9.

The urgency of the return spring 60 exerts a torce in addition to that of the atmospheric pressure to close and maintain cl-osed the contacts of the vacuum power switch 11. Likewise, the urgency of the return spring 613 exerts a force in addition to atmospheric pressure to close and maintain closed the contacts of the vac-num power switch .112. The force o-f the return compression springs 60 and 63 exerted on the heads 57 and 58, respectively, can be regulated by adjusting the heads relative to the operating rods 50 and 51, respectively. The return springs 60 `and 63 provide a more positive return and permit a selected return force to reduce arcing on the sliding operating rods. Y I

For opening the contacts of the vacuum power switch 11 against the urgency of the spring 60 and the atmospheric pressure, an inverted U-shaped contact actuating member 6-5 has an opening .65o therein to freely receive the actuating rod 50 and has the upper wall thereof disposed below the head 57 for engagement with the lower wall 57b of the head 57. One end o-f the contact actuating member 65 is attached to a bracket 66 by a pivot pin 67, which is fixed to the tubular coupling 23. The bracket 616 is stationary relative to the housing 20 and the sa-id one end of the .actuating member 65 is mounted for pivotal movement about the axis of the pin 67. The other end of the contact actuating member 6-5 is carried by a pin and is disposed between spaced toggle links 71 and 72 that also receive the pin 70. Cotter pins prevent axial displacement of the toggle links 71 and 72 relative to the pin 70.

Attached to the actuating member 65 by screws 75 is a depending bracket 66, which has a switch actuating arm or pull rod 73 axed thereto by screws 74. The switch actuating arrn 73, which is a single pull rod made of insulating moisture resistant high strength epoxy glass or other similar material, moves with said other end of the actuating member 65 in a longitudinal direction relative to the housing 20. By making the -rod 73` insulated and moisture resistant, electrical paths that cause shorts are eliminated.

At the lower end of the switch actuating arm 73 is secured a bracket 7-6. A contact actuating member 77 having inverted U-shaped conguration has one end thereof received by a pin 78, which is carried by the bracket 76'. Cotter pins prevent axial displacement of the actuating member 77 relative to the pin 78. Said one end of the actuating member 77, therefore, moves with the movement of the actuating arm 73.

The other end of the actuating member 77 is supported for pivotal movement by a pin 80, which is carried by a bracket 81. The bracket 81 is xed to the tubular coupling 40. Thus, the bracket 81 is in fixed relation with the housing 20 and said other end of the actuating member 77 is supported for pivotal movement about the axis of the pin 80.

For opening the contacts of the vacuum power switch 12 against the urgency of the spring 63 and atmospheric pressure, the Contact actuating member 77 has an opening 77a therein to freely receive the actuating rod 51 and has the upper wall thereof disposed below the head 58 for engagement with the lower wall 58b of the head 58. v A suitable opening is also formed in the plate 39 and the tubular coupling 40 to freely receive the switch actuating arm 73.

From the foregoing, it is to be observed that when the switch actuating arm 73 is in the lower position, as shown in FIG. l, the free ends of the contact actuating members 65 and 77 are lowered. Consequently, the contacts of the vacuum power switch 11 are closed under the .urgency of the spring 60, in addition to the atmospheric pressure, which had moved the head 57 and the operating rod 50 downwardly and maintains them in the lowered position. Likewise, the contacts of the Vacuum power switch 12 are closed under the urgency of the spring 63, in addition to the atmospheric pressure, which had moved the head 58 and the operating rod 51 downwardly and maintains them in the lowered position.

The contact actuating members 65 and 77 move in unison with the switch actuating arm 73. When the switch actuating arm 73 is in its raised position, the free ends of the contact actuating members 65 and 77 are in the raised positions. This action causes the contact actuating member 65 to engage the head 57 and to raise it against the urgency of the spring 60 land the atmospheric pressure. In so doing, Ithe operating rod 50 is raised and the contacts of the vacuum power switch 11 are opened. Likewise, this action causes the contact actuating member 77 to engage the head 58 land to raise it against the urgency of Ithe spring 63 and the atmospheric pressure. In so doing, the operating rod 51 is r-aised and the coutacts of the vacuum power switch 12 are opened. The arcuate walls 57b and 58h of the heads 57 and 58, respectively, provide a centering action for the actuating members 65 and 77, respectively, to control in part the opening speed of the contacts and the timing of the opening of the contacts.

For moving the switch actuating arm 73 and the contact actuating members 65 and 77 simultaneously, switch actuating linkage 90 is provided, which comprises a lift rod or operating lever 91. The lever 91 may be used to operate the mechanism, but the mechanism may be tripped or reset by other means and remote operations. The lever 91 at the proximal end thereof is iXedly secured to a shaft 92 by a nut 93, whereby pivotal movement of the lever 91 imparts a rotary movement to the shaft 92. It is to be observed from FIGS. 2 and 3 that the shaft 92 has a reduced diameter portion.

The shaft 92 is supported for rotation by the housing 20. At one end, the shaft 92 has a further reduced diameter section that is received by an opening in the cylindrical Wall of the housing 20. Adjacent thereto, is a sleeve or spacer 94 made of epoxy, Delrin or similar insulating material that -receives the shaft 92 for free rotation. The other end of the shaft 92 is received by a bushing or spacing 95 which receives the shaft 92 for free rotation. The bushing 95 is made of epoxy, Delrin or similar insulating material. Adjacent the bushing 95 is a suitable resilient washer 96. By employing the moisture resistant insulating bushing and sleeves 95 and 94, high mechanical "strength is attained with low moisture penetration and also low friction. The prevention of moisture accumulat- Ving in the housing 20 makes the vacuum switch 10 corrosion proof. In addition, corrosion of the other electrically conducting parts is prevented. By eliminating the gal- ,vanic action between associated electrically conducting members by use of insulation between them, dangerous lcorrosion is prevented.

Mounted in spaced relation on the shaft 92 for move- "ment therewith 'are ears or depending members 100 and 101. The ears 100 and 101 are adjustably mounted on the shaft 92 by screws for angularly displacement relative to the shaft 92. At the lower portions of the ears 100 and 101 are fixed inwardly directed anchor pins 102 and 103, respectively. Anchored to the pins 102 and 103 are force transmitting or pull springs 104 and 105, respectively. The lower ends of the springs 104 and 105 are anchored to a shaft 106. The shaft 106 in turn is v,received by the toggle links 71 and 72. As previously described, the toggle links 71 and 72 are connected to the contacts actuating member 65 through the pivot pin 70 and the contact actuating member 65 is connected to the "switch actuating arm 73 through the bracket 66. The toggle links-71 and 72 at the proximal ends thereof are connected by a pivot pin 107 `to toggle links 108 and 109, which Vare connected by a shaft 110 to the block 62. The Ytoggle links 71, 72, 108 .and 109 provide a toggle actuating mechanism.

'f When the lift rod 91 is actuated to rotate the shaft 92 in the direction 'shown by an arrow 115' (FIG. 1), the lears 100 and 101 rotate with the shaft 92. This action causes `a pulling force transmitted through the springs 104 "and 105 to pivot the toggle links 108, 109, 71 and 72 and elevate the free ends thereof. Consequently, the contact actuating member 65, the switch actuating avm 73 and the contact actuating member 77 are raised at the free ends l thereof to open the contacts of the vacuum power switches 11 and 12.. l

l Anchored to the pin 102 and the bracket 61 is a return yspring 116. When the lift rod 91 is actuated to the conjtact opening position, the return spring 116 is tensioned. AThe return spring 116 serves the purpose of providing less jarring and maintaining al return force on the lift rod 91. L' After'the lift rod 91` is released,- it is returned to its initial position by the return spring 116 to allow operation in any position. Consequently, the shaft 92 and the ears and 101 are returned to their reset positions. The toggle links 71, 72, 108 and 109 are returned to their reset positions through the action of the springs 104-106. Hence, the actuating members 65 and 77 and the actuating arm springs 104 will have their free ends lowered, and thus the toggle links are actuated to the contact closing position. The contacts of the vacuum power switches 11 and 12 are assisted inl closing before the toggle linkage is reset through the action of the compression coil springs 60 and 63 against the heads 57 and 58, respectively. Atmospheric pressure also causes the closing of the contacts in switches 11 and 12.

The trip and reset timing for the toggle links 71, 72, 108 and 109 relative to the movement of the pull rod 91 is regulated and controlled by the actions of the springs 104 and 105. In addition, the speed of travel of the toggle links between the respective positions is regulated by the actions of the springs 104 and 105.

'Io adjust the Itension of the springs 104 and 105, the angle of the springs 104 and 105 is varied relative to the toggle links 71, 72, 108 'and 109, and the point on the toggle links to which they are fastened is also varied. The forces of the springs 104 and 105 vary between the trip and return positions. By rotating the ears 100 and 101 to selected langular settings relative to the sha-ft 92, the angle of the springs 104 and 105 relative to the toggle links can be adjusted and thereby the tension of the springs 104 and `105 is adjusted. This can also be accomplished by setting the lift rod 91 relative to the shaft 92, since the initial position tof the lift rod 91 will always be the same under the force .of the return spring 116. The foregoing steps will also adjust the tension of the release spring 116.

Mounted on the shaft 92 between the link 109 and the ear 101 is a locking cam 1-20. The locking cam 120 is adjustably mounted |on the shaft 92 by a screw 121. However, the cam is fixed to the shaft 92 for movement therewith. At the bevelled wall 120a thereof, the locking cam 120 engages 'the center end of the toggle link 72 (FIG. 2). The locking cam 120 provides an Iadjustable trip as well as prevent the pre-closure as operating spring forces and angles are adjustably varied, when adjustments are necessary to obtain closely controlled trip and closing angles for operating actuating arm 65 between contact opening and contact closing.

In the operation of the vacuum switch 10, the contacts of the vacuum power switches 11 and 12 are initially and normally closed. For interrupting or opening the contacts of the vacuum power switches 411 and 12, the lift rod 91 is Iactuated to rotate the shaft 92 in the direction shown by the arrow 115. As a consequence thereof, the ears 100 and 101 rotate with the shaft 92 to apply forces to toggle links 71, 72, 108 and 109 through the springs104 and 105.

Thereupon, the free ends of the links 71 and 72, the .free end of the contact actuating member 65, the switch actuating rod 73, and the lfree end of the contact actuating member 77 are raised. The raising of the free ends of the contact actuating rnembers 65 and 77 causes the heads 57 and 58, respectively, to be elevated against the action of the springs 60 and 63 and also gains atmospheric pressure. This results in the lifting of the operating rods 50 and 51, respectively, to open the contacts of the vacuum power switches 11 and 12.

When the lift rod 91 is released, the springs 60 and 63 and 'atmospheric pressure cause the heads 57 and 58, respectively, to lowe-r, thereby Ilowering the contact rods 50 and 51, respectively, to close the contacts of the vacuum power switches 11 and 12. As the contacts are closed, fthe return spring 116 with the help of the springs 104 and 105 return the shaft 92, the ears 100 and 101 to their initial or reset positions. Through the resiliency of the springs 104-106, the toggle 4'links 71, 72, 1108 and 109 are returned to Itheir initial or reset positions. Hence, the contact actuating members 65 and 77 at the free ends thereof and the switch actuating arm 73 are in their lowered positions.

While components are shown screwed together to form a unitary structure, it is apparent that such components may be integrally formed by castings `and the like.

It is to be understood that modifications and variations of the embodiments of the inventions disclosed herein may be resorted to without departing from the spirit of the invention and 'the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. A switch comprising a housing, an electrical switch mounted in said housing, mechanical linkage for actuating said electrical switch, a pull spring connected to said linkage for activating the sarne to actuate said electrical switch, said pull spring being disposed at an angle relative to said linkage and adjustable on said linkage, a shaft mounted in said h-ousing at an initial position, rotating means connected to said shaft for imparting rotary movement thereto from, said initial position, rneans mounted on said shaft and connected to said pull spring for activating said :linkage in response to the rotation of said shaft, and a return spring connected to said last-mentioned means and opposi'tely directed relative to said pull spring for returning said shaft to its initial position.

2. A switch comprising a housing, an electrical switch mounted in said housing, mechanical linkage 'for actuating said electrical switch, a spring connected to said linkage for activating lthe same to actuate said electrical switch, said spring being disposed vat an angle relative to said linkage and adjustably fastened to said linkage, a shaft mounted in said housing, means connected to said shaft for imparting `ro-tary movement thereto, and means mounted on said shaft for movement therewith and adjustably positioned angularly on said shaft, said last- -mentioned means being connected to said spring to tension said spring for activating said linkage, `the angular adjustment of said last mentioned means controls the relative angle between said spring and said linkage, whereby the activating time Iand .force of said linkage relative to the rotary movement of said shaft is regulated.

3. A switch comprisingfa housing, an electrical switch vmounted in said housing, mechanical linkage for actuating said electrical switch, Ia spring connected to said linkage for activating the same -to actuate said electrical switch, said spring being disposed at an angle relative to said linkage and -adj-ustably fastened to said linkage, a shaft mounted in said housing, means mounted on said shaft and connected to said spring for activating said linkage in response to lthe rotation of said shaft, a lift rod connected to said shaft for imparting rotary movement thereto and angularly 'adjusted relative to said shaft for controlling `the angle between said spring and said linkage, whereby the activating time of said linkage relative to the rotary movement of said shaft is regulated, and cam means mounted on said shaft in engagement with said means connected to said spring to control .the activation of Isaid linkage.

4. A switch comprising a housing, an electrical switch mounted in said housing, mechanical linkage for actuating said electrical switch, a pull spring connected to said linkage for activating the same ,to actuate said electrical switch, said pull spring being disposed at an angle relative to said linkage and adjustably fastened to said linkage, a shaft mounted in said housing at an initial position, means connected to said shaft for imparting rotary movement thereto from said initial position, rotating means mounted on said shaft for movement therewith and adjustably positioned angularly on said shaft, said last-mentioned means being connected to said pull spring to tension said pull spring for activating said linkage, and a return spring connected to said last-mentioned means and oppositely directed relative to said pull spring for returning said shaft to its initial position, the angular adjustment of said last-mentioned means controls the relative angle between said linkage and said pull spring and return spring.

5. A switch comprising a housing, an electrical switch mounted in said housing, toggle linkage for actuating said electrical switch, a spring adjustably connected to said toggle linkage for activating the same to actuate said electrical switch, said spring being disposed at an angle relative to said toggle linkage, a shaft mounted in said housing, means connected to said shaft for imparting rotary movement thereto, and means mounted on said shaft for movement therewith and adjustably positioned angularly on said shaft, said last-mentioned means being connected to said spring to tension said spring for activating said toggle linkage, the angular adjustment of said last-mentioned means controls the relative angle between said spring and said toggle linkage, whereby the activating time and force of said toggle linkage relative to the rotary movement of said shaft is regulated.

6. A switch comprising a housing, a first and second electrical switch mounted in tandem within said housing, a pull rod disposed within said housing adjacent said first and second electrical switch, a first actuating arm pivotally mounted in said housing at its proximal end and having its free end connected to said pull rod, first means including a head with an arcuate wall engaging said first arm and responsive to the pivotal movement thereof for actuating said first electrical switch, a second actuating arm pivotally mounted in said housing at its proximal end and having its free end connected to said pull rod, second means including a head with an arcuate wall engaging said second arm and responsive to the pivotal movement thereof for actuating said second electrical switch, and means for moving said pull rod, said first arm and said second arm simultaneously for actuating said first and second electrical switches.

7. A switch comprising a housing, -a first and second electrical switch mounted in tandem with said housing, a pull rod disposed within said housing adjacent said first and second electrical switches, a first actuating arm pivotally mounted in said housing at its proximal end and having its free end connected to said pull rod, first means including a first head with an upper shoulder and a lower arcuate wall engaging said first arm and responsive to the pivotal movement thereof for actuating said first electrical switch, a first spring engaging said shoulder of said first head for urging said first head downwardly, a second actuating arm pivotally mounted in said housing at its proximal end and having its free end lconnected to said pull rod, second means including a second head with an upper shoulder and a lower arcuate wall engaging said second arm and responsive to the pivotal movement thereof for actuating said second switch, a second spring engaging said shoulder of said second head for urging said second head downwardly, and means for moving said pull rod, said first and said second arm simultaneously against the urgency of said first and second springs for actuating said first and second electrical switches.

8. A switch comprising a housing, an electrical switch mounted in said housing, toggle linkage for actuating said electrical switch, a spring connected to said toggle linkage for activating the same to actuate said electrical switch, a shaft mounted in said housing above said spring, means connected to said shaft for imparting rotary movement thereto, and a depending member mounted on said shaft for movement therewith and connected to said spring for tensioning said spring in response to rotation of said shaft for activating said toggle linkage.

9. A switch comprising a housing, an electrical Switch mounted in said housing, mechanical linkage for actuating said electrical switch, a spring connected to said linkage for activating the same to actuate said electrical switch, a shaft mounted in said housing, means mounted on said shaft and connected to said spring for activating said linkage in response to the rotary movement of said shaft, a lift rod connected to said shaft for imparting rotary movement thereto, and a cam mounted on said shaft in engagement with said means connected to said spring to control the activation of said linkage.

10. A switch comprising a housing with a cylindrical outer wall, said cylindrical outer wall being formed with annular grooves therein, a base disposed within said housing, a support disposed Within said housing above said base, an electrical switch disposed within said housing and mounted on said support, a resilient member interposed between said base and said support to yield to lateral thrust, a metallic coupling with an inner cylindrical wall disposed Varound said cylindrical outer wall contiguous therewith, said coupling being formed with annular grooves in the inner wall thereof complementing the grooves formed in said cylindrical outer wall of said housing to form therewith rings, an adhesive disposed within the grooves of said housing and the grooves of said coupling for forming a seal between said housing and said coupling, an actuating mechanism disposed within said housing for operating said electrical switch, said actuating mechanism including a shaft supported by said housing for rotation, and a moisture resistant insulating sleeve disposed between said housing and said shaft for journalling said shaft for rotation and for establishing a seal between said shaft and said housing.

References Cited by the Examiner UNITED STATES PATENTS 715,428 12/ 1902 Schureman 200-4 1,491,885 4/ 1924 Robinson 200-168 2,468,974 5/ 1949 Hammer 200-168 X 2,604,554 7/ 1952 Jacobi 200-4 2,838,636 6/1958 Schwager f 200-144 X 2,873,332 2/ 1959 Williams 200-166 2,892,064 5/ 1959 Ostrom et al 200-168 3,096,423 7/1963 Wilson ZOO-168 3,101,207 8/1963 Pavel et al 285-55 X 3,123,698 3/1964 waterton 20o-144 3,178,542 4/ 1965 Jennings 200-144 3,182,160 5/1965 Zavertnik et al. 200-168 FOREIGN PATENTS 201,274 2/ 1956 Australia.

634,677 1/ 1962 Canada. 1,212,196 10/1959 France.

262,895 12/ 1926 Great Britain.

787,846 12/ 1957 Great Britain.

ROBERT K. SCHAEFER, Primary Examiner.

KATHLEEN H. CLAFFY, BERNARD A. GILHEANY,

Examiners. M. GINSBURG, Assistant Examiner. 

1. A SWITCH COMPRISING A HOUSING, AN ELECTRICAL SWITCH MOUNTED IN SAID HOUSING, MECHANICAL LINKAGE FOR ACTUATING SAID ELECTRICAL SWITCH, A PULL SPRING CONNECTED TO SAID LINKAGE FOR ACTIVATING THE SAME TO ACTUATE SAID ELECTRICAL SWITCH, SAID PULL SPRING BEING DISPOSED AT AN ANGLE RELATIVE TO SAID LINKAGE AND ADJUSTABLE ON SAID LINKAGE, A SHAFT MOUNTED IN SAID HOUSING AT AN INITIAL POSITION, ROTATING MEANS CONNECTED TO SAID SHAFT FOR IMPARTING ROTARY MOVEMENT THERETO FROM SAID INITIAL POSITION, MEANS MOUNTED ON SAID SHAFT AND CONNECTED TO SAID PULL SPRING FOR ACTIVATING SAID LINKAGE IN RESPONSE TO THE ROTATION OF SAID SHAFT, AND A RETURN SPRING CONNECTED TO SAID LAST-MENTIONED MEANS AND OPPOSITELY DIRECTED RELATIVE TO SAID PULL SPRING FOR RETURNING SAID SHAFT TO ITS INITIAL POSITION. 